The present invention relates to an assembling apparatus for slide fastener stringers used in forming a slide fastener chain by combining a pair of slide fastener stringers to be interengaged with each other at the individual interengagement elements thereof.
The prior art assembling apparatuses for such a purpose are provided with a pair of pulling rollers rotating coaxially at the same velocity and positioned close to each other, a binder member with a structure in its main part similar to that of a slider in a finished slide fastener positioned at the feeding side of the above mentioned pulling rollers and stoppers positioned before the entrance to the binder member which serve to align the starting terminals of the rows of the elements of both of the slide fastener stringers (see, for example German Patent Publication No. DE-AS 1225432).
Each of the slide fastener stringers fed to the apparatus is shaped in a continuous length, having space sections each of a predetermined length at predetermined intervals, and a right fastener stringer and a left fastener stringer are combined in the binder member into a slide fastener chain of interengaged stringers, being introduced into the binder member with the rows of the elements facing each other, after the leading elements of the rows of the elements of both of the fastener stringers have been brought into alignment, and the alignment being maintained as such, and the interengaged slide fastener chain being discharged from the binder member continuously by the pulling rollers.
In the alignment of the slide fastener stringers as above in conventional apparatuses, the progress of the leading fastener stringer (if one is ahead of the other) is interrupted by a stopper at its respective side for a while during which the trailing slide fastener stringer is forwarded to catch it up and, when both of the leading elements come into contact with the individual stoppers, the stoppers are moved aside to permit the progress of both of the fastener stringers.
The problems in the prior art apparatuses are that the once aligned stringers often come to be out of alignment before they are combined completely, causing mismatching of the elements because the alignment is performed before the stringers enter the binder member, and that some of the elements are displaced from their right positions where they have been secured to the carrier tapes because of the large impact force exerted on the elements of the leading stringer by the interruption of its progress at the stopper resulting in decreased reliability of the assembling process. Further, the productivity in the prior art apparatuses cannot be sufficiently high because an increased feeding velocity of the stringers results in an increased impact force to the elements coming into contact with the stopper to limit the feeding velocity as well as because quite a long time is taken for alignment of the leading elements of leading and trailing fastener stringers to limit the overall velocity of the apparatus.